1. Field of the Invention
The present invention relates generally to power supply units, and in particular, to a power supply unit which is capable of supplying power with a plurality of output voltage ranges. More particularity, the power supply unit includes a power-side regulator and one or more supply-side regulators. The power-side regulator generates a first intermediate voltage that is stepped-down from a power supply source. The supply-side regulator generates a power generated from the first intermediate voltage that has been stepped-down. The power supply unit is configured to supply the power to a controlled object.
2. Description of the Related Art
As a conventional power supply unit such as that described above, a device is disclosed in Japanese Patent Laid-open Publication No. 2004-147437 that is configured to generate a plurality of types of supply voltages to be supplied to a controlled object, depending on the combination of a power-side regulator and a supply-side regulator.
However, in the above-described configuration, the types of supply voltages that are ultimately generated, specifically a voltage range of each supply voltage, is determined depending on respective characteristics of the power-side regulator and the supply-side regulator. Therefore, no problems arise when the controlled object only requires the voltage range which is determined depending on the respective characteristics of the power-side regulator and the supply-side regulator. However, if the controlled object requires a supply voltage that exceeds the above voltage range, the power supply unit configured by the power-side regulator and the supply-side regulator cannot be used.
In such instances, a dedicated power supply unit that adapts an alternative voltage range necessary for the controlled object is newly developed. However, the cost of designing and manufacturing the dedicated power supply unit increases the final manufacturing cost of the controlled object.